我想改变一个C++项目,当我点击视图端口时,它正在绘制一些行。这个功能非常好,但是我想改变的是当我点击“UP”或“Down”键时,下一行的颜色会改变。目前,如果我点击这些键,所有行的颜色都会改变,包括旧的(已绘制)。OpenGL项目与drawPrimitive()
请给我一个做什么的想法。这里是一些代码:
void drawPrimitive() {
Vertex *temp;
// Set the primitive color
glColor3fv(primitiveColor);
// Set the point size in case we are drawing a point
if (type == POINT)
glPointSize(pointSize);
// Display results depending on the mode
glBegin(mode);
for(temp = head; temp != NULL; temp = temp->np)
{
if (smoothShading)
glColor3f(temp->r, temp->g, temp->b);
glVertex2f(temp->x, temp->y);
}
glEnd(); }
void mouse(int button, int state, int x, int y) {
if(button == GLUT_LEFT_BUTTON && state == GLUT_DOWN)
{
float pointX, pointY;
pointX = (float)x/window_width * world_width;
pointY = (float)(window_height - y)/window_height * world_height;
// Add a vertex to the list of vertices...
addVertex(&head, &tail, pointX, pointY, 0.0f, primitiveColor[0], primitiveColor[1], primitiveColor[2]);
// automatically calls the display function
glutPostRedisplay();
}
else if(button == GLUT_MIDDLE_BUTTON && state == GLUT_DOWN)
{
deleteVertex(&head, &tail);
glutPostRedisplay();
} }
void special(int key, int x, int y) {
switch (key)
{
// change primitive color
case GLUT_KEY_UP :
changePrimitiveColor(1);
break;
case GLUT_KEY_DOWN :
changePrimitiveColor(-1);
break;
}
glutPostRedisplay(); }
void changePrimitiveColor(int step) {
primitiveColorId += step;
if (primitiveColorId < 0)
primitiveColorId = COLOR_COUNT - 1;
if (primitiveColorId >= COLOR_COUNT)
primitiveColorId = 0;
setColor(primitiveColor, primitiveColorId); }
我发现了一个类似于此的解决方案。当调用drawPrimitive()修改特征线的颜色时,我改变了这一点。 –